Floor covering materials have increased in popularity in recent years and are now frequently being manufactured in a variety of decorative appearances for coordination with the decor of the building in which they are installed. Along with increased variety of appearances, is the increased variety of textures available. Quite popular are the embossed floor coverings which have raised areas and depressions. Frequently these embossed floor covering materials have a foam interlayer which also gives a cushioned feel to the floor covering and in many cases even resembles the feel of textile carpets.
Most of the floor coverings now being sold have a surface or wearlayer of a polyester or polyvinyl halide resin such as polyvinyl chloride. Resins such as these are tough and resistant to a large variety of materials which are frequently spilled upon them.
Many of these types of floor coverings having a polyvinyl halide wearlayer also have a clear finish coating applied thereto to give the floor covering material a glossy appearance without the necessity of frequent waxing. This type of finish is applied in a number of ways such as by applying a durable wax to the surface at the time of manufacture or by applying a clear resinous type of finish to the wearlayer. Lacquers were frequently used to provide the gloss finish to the floor covering, however, more recently, polyurethane and polyvinyl chloride coatings have been applied for similar purposes. Such a coating has the advantages of durability and pleasing appearance. The finish coating must of course be clear to enable the multicolored decoration in the wearlayer to show through, and this is the case regardless of whether the surface coating is a lacquer, wax, acrylic, urethane, or other type of coating or polish.
Furthermore, when the surface of the floor covering is of the textured variety, the applied coating must not be so thick as to fill the indentations, for this would destroy the embossed feel and frequently, the embossed appearance, and actually less coating is needed here since less wear occurs in the valleys.
Many ways have been used previously for applying the finish coating to the goods. In the case of a flat surface covering, i.e. one which has not been embossed, a reverse roll coater may be used for applying the coating material. However, for embossed goods, a curtain coater or spray coater is usually used. Because of the nature of the apparatus, however, a curtain coater or spray applicator will tend to fill the indentations of an embossed sheet, and as indicated previously, this is deleterious to the desired product. Also, these types of coating apparatus are expensive and therefore increase the cost of the finished product.
Accordingly, a primary object of this invention is to provide a method for continuously applying a resinous surface coating to a web of floor covering material.
Another object of this invention is to provide a method for applying a polyurethane or polyvinyl chloride surface coating which overcomes the disadvantages of prior art methods.
A further object of this invention is to provide a method for applying a polyurethane or polyvinyl chloride surface coating which is inexpensive to set up and maintain.
Still another object of this invention is to provide a method for continuously applying a polyurethane or polyvinyl chloride surface coating which evenly coats the substrate across its width.
Still a further object of this invention is to provide a method for applying a polyurethane or polyvinyl chloride coating which does not result in filling the embossed areas of the coated substrate.
Yet a further object of this invention is to provide a method for applying a polyurethane or polyvinyl chloride coating which does not result in streaked areas or flow marks in the coating.